Major Quake Looms for Ill-Prepared Oregon
'Oregon is not ready,' says an expert
By Evann Gastaldo,  Newser Staff
Posted Aug 2, 2012 8:48 AM CDT
Updated Aug 5, 2012 12:48 PM CDT
The Romanesque-style tower of Union Station, with flags on top, is silhouetted against the city skyline in Portland, Ore., Tuesday, Feb. 2, 2010.   (AP Photo/Don Ryan)

(Newser) – Oregon is sitting on a ticking time bomb, and stands a 40% chance of getting hit by a major earthquake—possibly as big as the one that hit Japan last year—in the next half-century, according to an ominous new report out of Oregon State University. Adding to concern: Shaking will likely go on for three to five minutes in a state where seismic design standards often only account for 30 seconds of shaking. "Oregon is not ready," one expert tells the Oregonian. Liquefaction, which can cause buildings to sink, is another potential problem, as are impassable roads and collapsed schools.

The chance of an earthquake of magnitude 8.1 to 8.3 is 40%, while the risk of a 9.0-magnitude quake is just 10%—but a shaker like that could affect the entire coast, and induce a devastating tsunami. It's all thanks to Oregon's offshore seismic fault, the Cascadia Subduction Zone, which—similar to Japan—has the capability to produce powerful "megathrust" quakes. And given that the state's last known quake was in 1700, it's overdue for one. "If the Cascadia fault had a warranty against failure, it would have expired many years ago," says the study's lead author. Experts have been making similar predictions for years, but this time they have been published by the US Geological Survey, meaning that they will likely be considered in building code revisions.